After selecting to play in sandbox mode, three starting locations are given. You may choose to build your mall in a neighborhood, a big city, or beside the beach. One may also choose to play a campaign game instead, and select from several different challenges.
Interior view of mall in Career Mode

Unlike in the previous installments of the series, Mall Tycoon 3 allows players to create customized stores. Over 40 types of stores of various types are available for placement in a pre-made store or a player may design their own, putting in everything from sale signs to the merchandise racks. Also customizable are the employees; their job capabilities and personal appearances are adjustable. In addition to regular in-line stores, there are also a handful of kiosks, such as one that sells cellular phones.

In the first two Mall Tycoon games, stores were created by placing the set store size, and then adding a store to them. In Mall Tycoon 3, the player paints the floor to create a store, allowing for them to be of any shape or size.